Hypothetical regional extraction analysis of long-term interregional trade shifts in the Chubu Region, Japan

Abstract This study visualizes long-term shifts in interregional trade between Ishikawa Prefecture in the Hokuriku region and Aichi Prefecture in the Tokai region, focusing on their trade relationships with other prefectures in the Chubu region. Using the hypothetical regional extraction method and multiregional input–output tables for five time points (1995, 2000, 2005, 2011, and 2015), the economic effects of hypothetically removing these prefectures from the regional production network were analyzed. The analysis revealed that interregional trade within the Chubu region expanded in both prefectures after 2011 despite a substantial decline in production owing to the Great East Japan Earthquake. By 2015, production levels had recovered to approximately the same level as in 2005, and the trend of increasing interregional trade continued. Thus, the expansion in interregional trade observed after 2011 was not temporary; both Ishikawa and Aichi prefectures have since strengthened their trade relationships with other prefectures in the Chubu region. Positioning the Great East Japan Earthquake within the international literature on disaster propagation through production networks, this paper provides a comparable, multi-period indicator of interregional embeddedness and its persistence after large shocks. It also highlights the importance of resilient interregional trade networks in mitigating future disruptions, offering policy-relevant insights.